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1da177e4 LT |
1 | /* |
2 | * llc_if.c - Defines LLC interface to upper layer | |
3 | * | |
4 | * Copyright (c) 1997 by Procom Technology, Inc. | |
5 | * 2001-2003 by Arnaldo Carvalho de Melo <acme@conectiva.com.br> | |
6 | * | |
7 | * This program can be redistributed or modified under the terms of the | |
8 | * GNU General Public License as published by the Free Software Foundation. | |
9 | * This program is distributed without any warranty or implied warranty | |
10 | * of merchantability or fitness for a particular purpose. | |
11 | * | |
12 | * See the GNU General Public License for more details. | |
13 | */ | |
14 | #include <linux/config.h> | |
15 | #include <linux/module.h> | |
16 | #include <linux/kernel.h> | |
17 | #include <linux/netdevice.h> | |
1da177e4 LT |
18 | #include <asm/errno.h> |
19 | #include <net/llc_if.h> | |
20 | #include <net/llc_sap.h> | |
21 | #include <net/llc_s_ev.h> | |
22 | #include <net/llc_conn.h> | |
23 | #include <net/sock.h> | |
24 | #include <net/llc_c_ev.h> | |
25 | #include <net/llc_c_ac.h> | |
26 | #include <net/llc_c_st.h> | |
c752f073 | 27 | #include <net/tcp_states.h> |
1da177e4 LT |
28 | |
29 | u8 llc_mac_null_var[IFHWADDRLEN]; | |
30 | ||
31 | /** | |
32 | * llc_build_and_send_pkt - Connection data sending for upper layers. | |
33 | * @sk: connection | |
34 | * @skb: packet to send | |
35 | * | |
36 | * This function is called when upper layer wants to send data using | |
37 | * connection oriented communication mode. During sending data, connection | |
38 | * will be locked and received frames and expired timers will be queued. | |
39 | * Returns 0 for success, -ECONNABORTED when the connection already | |
40 | * closed and -EBUSY when sending data is not permitted in this state or | |
41 | * LLC has send an I pdu with p bit set to 1 and is waiting for it's | |
42 | * response. | |
43 | */ | |
44 | int llc_build_and_send_pkt(struct sock *sk, struct sk_buff *skb) | |
45 | { | |
46 | struct llc_conn_state_ev *ev; | |
47 | int rc = -ECONNABORTED; | |
48 | struct llc_sock *llc = llc_sk(sk); | |
49 | ||
50 | if (llc->state == LLC_CONN_STATE_ADM) | |
51 | goto out; | |
52 | rc = -EBUSY; | |
53 | if (llc_data_accept_state(llc->state)) { /* data_conn_refuse */ | |
54 | llc->failed_data_req = 1; | |
55 | goto out; | |
56 | } | |
57 | if (llc->p_flag) { | |
58 | llc->failed_data_req = 1; | |
59 | goto out; | |
60 | } | |
61 | ev = llc_conn_ev(skb); | |
62 | ev->type = LLC_CONN_EV_TYPE_PRIM; | |
63 | ev->prim = LLC_DATA_PRIM; | |
64 | ev->prim_type = LLC_PRIM_TYPE_REQ; | |
65 | skb->dev = llc->dev; | |
66 | rc = llc_conn_state_process(sk, skb); | |
67 | out: | |
68 | return rc; | |
69 | } | |
70 | ||
71 | /** | |
72 | * llc_establish_connection - Called by upper layer to establish a conn | |
73 | * @sk: connection | |
74 | * @lmac: local mac address | |
75 | * @dmac: destination mac address | |
76 | * @dsap: destination sap | |
77 | * | |
78 | * Upper layer calls this to establish an LLC connection with a remote | |
79 | * machine. This function packages a proper event and sends it connection | |
80 | * component state machine. Success or failure of connection | |
81 | * establishment will inform to upper layer via calling it's confirm | |
82 | * function and passing proper information. | |
83 | */ | |
84 | int llc_establish_connection(struct sock *sk, u8 *lmac, u8 *dmac, u8 dsap) | |
85 | { | |
86 | int rc = -EISCONN; | |
87 | struct llc_addr laddr, daddr; | |
88 | struct sk_buff *skb; | |
89 | struct llc_sock *llc = llc_sk(sk); | |
90 | struct sock *existing; | |
91 | ||
92 | laddr.lsap = llc->sap->laddr.lsap; | |
93 | daddr.lsap = dsap; | |
94 | memcpy(daddr.mac, dmac, sizeof(daddr.mac)); | |
95 | memcpy(laddr.mac, lmac, sizeof(laddr.mac)); | |
96 | existing = llc_lookup_established(llc->sap, &daddr, &laddr); | |
97 | if (existing) { | |
98 | if (existing->sk_state == TCP_ESTABLISHED) { | |
99 | sk = existing; | |
100 | goto out_put; | |
101 | } else | |
102 | sock_put(existing); | |
103 | } | |
104 | sock_hold(sk); | |
105 | rc = -ENOMEM; | |
106 | skb = alloc_skb(0, GFP_ATOMIC); | |
107 | if (skb) { | |
108 | struct llc_conn_state_ev *ev = llc_conn_ev(skb); | |
109 | ||
110 | ev->type = LLC_CONN_EV_TYPE_PRIM; | |
111 | ev->prim = LLC_CONN_PRIM; | |
112 | ev->prim_type = LLC_PRIM_TYPE_REQ; | |
113 | rc = llc_conn_state_process(sk, skb); | |
114 | } | |
115 | out_put: | |
116 | sock_put(sk); | |
117 | return rc; | |
118 | } | |
119 | ||
120 | /** | |
121 | * llc_send_disc - Called by upper layer to close a connection | |
122 | * @sk: connection to be closed | |
123 | * | |
124 | * Upper layer calls this when it wants to close an established LLC | |
125 | * connection with a remote machine. This function packages a proper event | |
126 | * and sends it to connection component state machine. Returns 0 for | |
127 | * success, 1 otherwise. | |
128 | */ | |
129 | int llc_send_disc(struct sock *sk) | |
130 | { | |
131 | u16 rc = 1; | |
132 | struct llc_conn_state_ev *ev; | |
133 | struct sk_buff *skb; | |
134 | ||
135 | sock_hold(sk); | |
136 | if (sk->sk_type != SOCK_STREAM || sk->sk_state != TCP_ESTABLISHED || | |
137 | llc_sk(sk)->state == LLC_CONN_STATE_ADM || | |
138 | llc_sk(sk)->state == LLC_CONN_OUT_OF_SVC) | |
139 | goto out; | |
140 | /* | |
141 | * Postpone unassigning the connection from its SAP and returning the | |
142 | * connection until all ACTIONs have been completely executed | |
143 | */ | |
144 | skb = alloc_skb(0, GFP_ATOMIC); | |
145 | if (!skb) | |
146 | goto out; | |
147 | sk->sk_state = TCP_CLOSING; | |
148 | ev = llc_conn_ev(skb); | |
149 | ev->type = LLC_CONN_EV_TYPE_PRIM; | |
150 | ev->prim = LLC_DISC_PRIM; | |
151 | ev->prim_type = LLC_PRIM_TYPE_REQ; | |
152 | rc = llc_conn_state_process(sk, skb); | |
153 | out: | |
154 | sock_put(sk); | |
155 | return rc; | |
156 | } | |
157 |